feat: add support for sticky comment notifications

[LouisBrunner]

Resolves #21

[github-actions]

## Smart Diff (Works): Success

Check succeeded with tolerance better (expected same or better)

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file4_added.txt
@@ -1,4 +1,5 @@
 A
 B
 C
 D
+E

[github-actions]

## Smart Diff (Fails (sticky)): Failure

Expected tolerance same but got worse instead

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file2_deleted.txt
@@ -1,4 +1,3 @@
 A
-B
 C
 D

[github-actions]

## Smart Diff (Fails): Failure

Expected tolerance same but got worse instead

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file2_deleted.txt
@@ -1,4 +1,3 @@
 A
-B
 C
 D

[github-actions]

## Smart Diff (Works (sticky)): Success

Check succeeded with tolerance better (expected same or better)

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file4_added.txt
@@ -1,4 +1,5 @@
 A
 B
 C
 D
+E

[github-actions]

Smart Diff (Fails): Failure

Expected tolerance same but got worse instead

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file2_deleted.txt
@@ -1,5 +1,3 @@
 A
-B
 C
 D
-ABC

[github-actions]

Smart Diff (Works (sticky)): Success

Check succeeded with tolerance better (expected same or better)

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file4_added.txt
@@ -1,4 +1,5 @@
 A
 B
 C
 D
+E

[github-actions]

Smart Diff (Works): Failure

Expected tolerance same but got mixed instead

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file4_added.txt
@@ -1,5 +1,5 @@
 A
 B
 C
 D
-ABC
+E

[github-actions]

Smart Diff (Fails (sticky)): Failure

Expected tolerance same but got worse instead

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file2_deleted.txt
@@ -1,4 +1,3 @@
 A
-B
 C
 D

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

Smart Diff (Fails): Failure

Expected tolerance same but got worse instead

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file2_deleted.txt
@@ -1,4 +1,3 @@
 A
-B
 C
 D

[github-actions]

Smart Diff (Works): Success

Check succeeded with tolerance better (expected same or better)

===================================================================
--- fixtures/file1_basic.txt
+++ fixtures/file4_added.txt
@@ -1,4 +1,5 @@
 A
 B
 C
 D
+E